He has said no more death warrants will be signed until the commission completes its final report in March.

The move came after the drawn-out death by lethal injection of Puerto Rican-born Diaz on Wednesday.

Diaz was sentenced to death for the 1979 murder of a Miami strip club manager.

Witnesses said his death took more than twice the usual time - 34 minutes rather than the usual 15.

He needed a second dose of the lethal chemicals as the needles were injected straight through his veins and into the flesh of his arms.

Following the autopsy, the medical examiner concluded the injections had been wrongly administered.

He was found to have large chemical burns on both arms and his lawyer reported that the 55-year-old continued to move and mouth words more than 20 minutes after the initial dose.

Inmates are supposed to be rendered unconscious by the chemicals within three to five minutes.

Anti-death penalty activists say lethal injections - introduced in Florida and other states as a replacement for the electric chair and other methods of execution - are just as cruel and should not be considered a more humane substitute.

But the BBC's Emilio San Pedro, in Miami, says that it is too soon to interpret the decisions as a sign that support for the death penalty is waning in the US.

Executions, he says, continue to be seen as the best deterrent of violent crime.